In the United States, up to seven million people have a food allergy, and about two million of them are children. Allergies account for about 30,000 emergency room visits per year, and food allergen
alerts accounted for nearly 30 percent of all food recalls and notifications in 2016, according to the U.S. Department of Agriculture Food
Safety and Inspection Service. Therefore, food processors have been
struggling to be able to identify and eliminate the allergens most
likely to cause these reactions.
The “gold standard” method for allergen detection is the enzyme-linked immunosorbent assay (ELISA). ELISA works by using specific
antibodies associated with a suspected allergen to generate a precise, proportional signal to the allergen level. While ELISA can detect
very small amounts of allergen, ELISA tests are specific for only that
allergen. In addition, ELISA testing can take several hours and requires sophisticated laboratory training and experience.
Three other technologies can also assess allergen risk. These other
technologies do not detect levels of allergens as low as ELISA, but
three Hygiena techniques can quickly detect the presence of any
protein or use proxy molecules like adenosine triphosphate (ATP) to
determine the existence of allergen-containing residues on a surface.
ATP Sanitation Monitoring
Detection of ATP, the energy-delivering molecule of living cells, is a
measure of the presence of any protein or organic matter, but it cannot differentiate between allergens or between nonallergenic organic
materials. Sensitive systems, like the SuperSnap™ High-Sensitivity
Surface ATP Test with the EnSURE™ Monitoring System, use ATP as a
proxy measure of proteins at levels that could indicate the presence
The Biuret Test (Piotrowski’s Test)
Biuret is a method in which a reagent turns from green to violet
when it comes into contact with certain amino acids (a certain sign
of protein presence). Tests based on this method, like the AllerSnap™
High-Sensitivity Allergen Prevention test, cannot distinguish between
proteins but can provide a “yes-no” colorimetric answer to determine
whether a potential allergen-containing residue is present.
These “dipstick”-like devices are convenient and fast, and indicate
the existence of certain allergens by a color change. Tests need to be
specific, like Hygiena’s AllerFlow Gluten (which determines the presence of gluten or gliadin proteins), and are more affordable, quicker,
and more convenient than ELISA tests.
Comparative Results for Allergen Detection
Hygiena researchers recently showed that, while not approaching
the level of detection of ELISAs, general protein and enhanced sensitivity ATP systems can determine the possible presence of allergens
at levels low enough for the investigation of specific proteins.
Researchers compared a range of ELISA tests for allergens against
the EnSURE Monitoring System with
the SuperSnap ATP test devices and the
AllerSnap Allergen Prevention Test. Eleven
major allergens were tested in a variety
of foods to determine the minimal levels
needed for detection. Of the allergens
tested, almonds were detectable at lower
or equal levels than ELISA testing by Su-
perSnap and AllerSnap.
For most allergens, it is not certain
what levels can begin causing health
issues in sensitive people. Currently, glu-ten/gliadin is the only allergen that has
a regulated level— 20 ppm—below which
the product is considered “gluten-free.”
Therefore, even a nonspecific reading that
indicates possible protein presence can
be a valuable piece of information in the
overall allergen-prevention program.
No matter what technique is used,
allergen control and prevention must be
part of an overall management program:
a plant design that allows easy cleaning
and sanitizing with no locations that allow the accumulation of debris, validated
cleaning verification procedures, and
plans regarding storage, handling, processing, packaging and identification of
allergenic foods and ingredients. Any control plan must be audited, enforced and
updated continually, and management
and staff need to verify their education on
these procedures and compliance with
the overall plan.
Effective allergen control and prevention will require more than one test.
The elusive nature, small quantities and
complex sources of allergens require a
sophisticated approach, consisting of
a number of different techniques that
can detect both specific and nonspecific
contaminants from product residues. Examples of cost-effective systems include
high-sensitivity ATP measurement, high-sensitivity nonspecific protein detection
and specific allergens tests in convenient
lateral flow strip formats.
A robust allergen detection and prevention plan, in turn, must be part of a
comprehensive food safety management
structure, which includes methods to
identify evidence of incomplete cleaning,
signs of potential bacterial pathogens
and identification of indicator organisms
and pathogens. Like any other health and
safety strategy, allergen detection that’s
based on prevention is better than a cure,
saving time, money and lives.
Allergen Detection Requires a